#include <stdio.h>
int peach(int day)
{
  int x = 1;
  if (day == 10)
  {
    return x;
  }
  else
  {
    return  (peach(day + 1) + 1) * 2;
  }
}
int main()
{
  int day;
  printf("请输入要查询的天数(0~9):");
  scanf("%d",&day);
  printf("第%d天有%d个桃子。",day, peach(day));
  return 0;
}